Hydrocarbon composition

ABSTRACT

A jet boiling range composition is provided with an unexpected distribution of carbon chain lengths for the hydrocarbons and paraffins in the composition. The hydrocarbon composition corresponds to a jet boiling range composition that includes 40 wt % or more of hydrocarbons and/or paraffins that have carbon chain lengths of 17 carbons or 18 carbons. Additionally or alternately, the hydrocarbon composition can contain 45 wt % or less of C14-C17 hydrocarbons and/or paraffins. This unexpected distribution of carbon chain lengths in a jet boiling range composition can be achieved for a composition that has a freeze point of −40° C. or lower and a flash point of 38° C. or higher. Optionally, the jet boiling range composition can also have a T10 distillation point of 205° C. or less (such as down to 150° C.) and a final boiling point of 300° C. or less

CROSS-REFERENCE TO RELATED APPLICATIONS

This non-provisional patent application claims priority to U.S.provisional patent app. No. 63/308,151, filed Feb. 9, 2022, and titled“HYDROCARBON COMPOSITION,” the entire contents of which is incorporatedherein by reference.

FIELD OF THE INVENTION

A jet boiling range hydrocarbon composition is provided, along withsystems and methods for producing such a composition.

BACKGROUND OF THE INVENTION

The aviation industry is looking for increasingly sustainable sources ofjet fuel to lower the carbon intensity of the fuel consumed duringflight. While the aviation industry today contributes 2-3% of global CO₂emissions, this is expected to increase with the anticipated growth ofthe aviation sector over the next 30 years. There are a number ofsustainable aviation fuel pathways that have been approved for use incommercial aviation.

Increased production of sustainable diesel fuel is also of generalinterest. Some renewable diesel products are already commerciallyavailable.

Renewable jet production is typically a multi-step process: eithersingle stage or two stage. In a first step, triglycerides, FAME, FFA arehydrotreated with conventional hydrotreating catalysts under typicalhydrotreating conditions to convert fatty acid chains to n-paraffins.The resulting n-paraffins are then exposed to a combination of dewaxingand cracking conditions (either as a single step or a plurality ofsteps) to form a hydroprocessed effluent. The hydroprocessed effluent isthen fractionated to produce naphtha, jet, and diesel boiling rangefractions.

Conventional methods for production of renewable jet generally use oneof two types of strategies. In one strategy, the goal is to primarilymake renewable jet fuel. Under this strategy, both cracking andisomerization are purposely performed on the feedstock, so that theresulting average carbon chain is both isomerized and reduced in chainlength. The other type of strategy is to make both jet and diesel duringa single process. Under this type of strategy, a fractionation ormulti-stage separation is used to separate naphtha, jet, and dieselboiling range fractions from the liquid products. In this type ofstrategy, cracking is not necessarily performed. However, the cut pointfor separation between the jet and diesel fractions is set relativelylow to avoid difficulties with meeting the freezing point limitationsthat are often included in the specification for a jet fuel.

The carbon chain length distribution for a renewable jet fractiontypically shows that C₁₁-C₁₂ carbon chains are the most common molecularsize in the renewable jet fraction. This is in contrast to a typicalconventional jet fuel derived from mineral sources, where the molecularsize distribution usually has a peak for C₁₃-C₁₄ chain lengths.

U.S. Pat. No. 7,846,323 describes a system and method for converting abio-derived feed to form a jet fuel fraction. The bio-derived feed ishydrotreated along with a recycle stream to form a hydrotreatedeffluent. The C₁₆+ portion of the effluent is then passed into ahydroisomerization reactor. The resulting hydroisomerization effluent isthen used as the recycled portion of the feed to the hydrotreater. Thespecification recites a temperature for hydroisomerization of 580° F. to680° F. (304° C. to 360° C.). However, the only example provided in thespecification actually uses a hydroisomerization temperature of 685° F.(363° C.).

U.S. Pat. No. 8,193,399 describes a system and method for converting abio-derived feed to form a jet and a diesel fraction. The bio-derivedfeed is introduced into an initial deoxygenation (hydrotreatment) stage,along with a sufficient amount of a recycled product stream to improvehydrogen solubility, so that low pressure operation can be performed.After deoxygenation, the deoxygenated liquid effluent is exposed to bothisomerization and hydrocracking conditions. Both a diesel product and ajet product are the separated from the isomerized and hydrocrackedeffluent. A portion of one or both of these products is used to providethe recycle stream.

U.S. Pat. No. 8,304,591 is directed to forming renewable fuels frombio-derived sources of fatty acids (such as glycerides) that includecarbon chains containing no more than 16 carbon atoms.

U.S. Pat. Nos. 8,314,274 and 8,742,183 describe methods for converting abio-derived feed to form a jet and a diesel fraction. Afterhydrotreatment to remove oxygen, the feed is hydroisomerized andhydrocracked. The hydrocracking and hydroisomerization can be performedas a single step if an appropriate catalyst is selected. Otherwise,separate cracking and hydroisomerization steps are performed.

U.S. Pat. No. 8,431,756 describes processing a bio-derived feed thatstill includes a substantial oxygen content with a dewaxing catalyst inorder to deoxygenate and/or isomerize the feed.

U.S. Pat. No. 8,523,959 describes processing a triglyceride-containingfeed via partial hydrodeoxygenation and optionally hydroisomerization toform fuels. The resulting fuels include an oxygen content of 0.001 wt %(10 wppm) or more. It is noted that the constraint of retaining oxygenin the final product limits the amount of hydroprocessing that can beperformed on the feed, due to the relative ease with which oxygen isremoved during any type of hydroprocessing.

U.S. Pat. Nos. 8,674,160 and 10,000,712 describe general hydroprocessingof a wide range of bio-derived feedstocks to form diesel fuels withimproved cold flow properties.

U.S. Pat. No. 8,729,330 describes exposing mixtures of a bio-derivedfeed having substantial oxygen content and a mineral feed to adewaxing/isomerization catalyst.

U.S. Pat. No. 9,617,479 describes hydrodeoxygenation of a wide range oftriglyceride-containing feeds under conditions that preserve oxygenand/or olefin content in the feed during hydrodeoxygenation. This canallow for recovery of increased amounts of propylene versus propane whenprocessing triglycerides. The resulting hydrodeoxygenated product canundergo further hydroprocessing.

U.S. Pat. No. 10,053,639 describes producing both a jet fuel product anda diesel fuel product from a feedstock. The feedstock can optionallyinclude a bio-derived portion.

U.S. Patent Application Publication 2008/0066374 describes processing ofbio-derived feeds over catalysts including both a catalytic metalfunction and an acidic function to form diesel fuels. Several examplesof processing of soybean oil are provided.

International Publication WO 2021/099343 describes processingbio-derived feeds containing C₁₂ to C₂₄ hydrocarbons to form a renewablehydrocarbon composition for use as a jet fuel blending component. Thefeed is hydrodeoxygenated and hydroisomerized. The resultinghydroprocessed effluent is then typically fractionated to separateheavier (i.e., diesel) boiling range components from a jet boiling rangefraction. The hydrocarbon composition is described as having an averagecarbon number of 14.3 to 15.1. This is apparently achieved by havingmore than 60 wt % of the hydrocarbon composition correspond to C₁₄ toC₁₇ hydrocarbons.

U.S. Pat. Nos. 6,759,438 and 5,151,371 describe a technique forperforming gas chromatography-atomic emission detection (GC-AED).

SUMMARY

In an aspect, a jet boiling range composition is provided. Thecomposition includes 40 wt % or more of C₁₇-C₁₈ hydrocarbons and 45 wt %or less of C₁₄-C₁₇ hydrocarbons. The composition has a T10 distillationpoint of 205° C. or less, a T90 distillation point of 300° C. or less, adensity of 765 kg/m³ or more, a flash point of 38° C. or more, and afreeze point of −40° C. or less. Additionally, the composition contains90 wt % or more of isoparaffins. Optionally, the composition has a finalboiling point of 300° C. or less.

In another aspects, a method for producing a jet boiling range fractionis provided. The method includes contacting a bio-derived feedstock witha hydrotreatment catalyst under effective hydrotreatment conditions toproduce a deoxygenated effluent containing a deoxygenated liquidfraction. The bio-derived feedstock can include 70 wt % or more of C₁₇+carbon chains. The method further includes contacting at least a portionof the deoxygenated liquid fraction with a dewaxing catalyst includingZSM-48 and Pt, Pd, or a combination thereof under effective dewaxingconditions to produce an isomerized effluent. The effective dewaxingconditions can include a weighted average bed temperature of 300° C. to350° C., a pressure of 1.4 MPa-g to 14 MPa-g, and a LHSV of 1.0 hr⁻¹ to8.0 hr⁻¹ relative to a weight of dewaxing catalyst. Additionally, themethod includes separating the isomerized effluent to form the jetboiling range fraction and one or more lower boiling fractions. The jetboiling range fraction can include 40 wt % or more of C₁₇-C₁₈hydrocarbons and 45 wt % or less of C₁₄-C₁₇ hydrocarbons. The jetboiling range fraction can have a T10 distillation point of 205° C. orless, a T90 distillation point of 300° C. or less, a density of 765kg/m³ or more, a flash point of 38° C. or more, and a freeze point of−40° C. or less. Additionally, the jet boiling range fraction cancontain 90 wt % or more of isoparaffins. Optionally, the jet boilingrange fraction has a final boiling point of 300° C. or less.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows an example of a reaction system for producing a renewablejet boiling range fraction.

FIG. 2 shows another example of a reaction system for producing arenewable jet boiling range fraction.

DETAILED DESCRIPTION Overview

In various aspects, a jet boiling range composition is provided with anunexpected distribution of carbon chain lengths for the hydrocarbons andparaffins in the composition. The hydrocarbon composition corresponds toa jet boiling range composition that includes 40 wt % or more ofhydrocarbons and/or paraffins that have carbon chain lengths of 17carbons or 18 carbons. In other words, the hydrocarbon compositioncontains 40 wt % or more of C₁₇-C₁₈ hydrocarbons, or 50 wt % or more, or60 wt % or more, or 70 wt % or more, such as up to 85 wt % or possiblystill higher. Additionally or alternately, the hydrocarbon compositioncan contain 45 wt % or less of C₁₄-C₁₇ hydrocarbons and/or paraffins, or40 wt % or less, or 35 wt % or less, such as down to 25 wt % or possiblystill lower. This unexpected distribution of carbon chain lengths in ajet boiling range composition can be achieved for a composition that hasa freeze point of −40° C. or lower and a flash point of 38° C. orhigher. Preferably, the jet boiling range composition can also have aT10 distillation point of 205° C. or less (such as down to 150° C.) anda final boiling point of 300° C. or less. Preferably, the jet boilingrange composition can have a density at 15° C. of 765 kg/m³ or more, or768 kg/m³ or more, or 770 kg/m³ or more, such as up to 775 kg/m³ orpossibly still higher. This unexpected combination of properties isachieved in part based on the fact that substantially all of theparaffins in the hydrocarbon composition correspond to isoparaffins,with n-paraffins corresponding to 10 wt % or less of the C₁₂₊hydrocarbons in the composition (relative to the weight of the C₁₂₊hydrocarbons), or 5.0 wt % or less of the C₁₄₊ hydrocarbons in thecomposition (relative to the weight of the C₁₄₊ hydrocarbons), or 5.0 wt% or less of the C₁₂₊ hydrocarbons in the composition (relative to theweight of the C₁₂₊ hydrocarbons), or 3.0 wt % or less of the of the C₁₄₊hydrocarbons in the composition (relative to the weight of the C₁₄₊hydrocarbons), such as down to having substantially no content of C₁₂₊or C₁₄₊ n-paraffins (0.1 wt % or less). In some aspects, the hydrocarboncomposition can contain 2.5 wt % or less of C₁₉₊ hydrocarbons, or 1.5 wt% or less, or 1.0 wt % or less, or 0.5 wt % or less, such as down tohaving substantially no content of C₁₉₊ hydrocarbons (0.1 wt % or less).

The hydrocarbon composition can be formed by processing a bio-derivedfeed that contains a high proportion of C₁₇₊ carbon chains. Preferably,the bio-derived feed can include a high proportion of C₁₇-C₁₈ carbonchains while containing a reduced or minimized amount of C₁₉₊ carbonchains. In aspects where a larger amount of C₁₉₊ carbon chains arepresent in the bio-derived feed, a fractionation or other separationthat allows for separation of the hydrocarbon composition from a heavierfraction (e.g., a diesel boiling range fraction) may be used. This canallow the hydrocarbon composition to remain in the jet boiling rangewhen a heavier feedstock is used.

During processing of the bio-derived feedstock, the feedstock can beexposed to hydrotreating conditions (for deoxygenation) followed bycatalytic dewaxing. The catalytic dewaxing conditions can be selected toprovide sufficient severity for substantially complete conversion ofn-paraffins to isoparaffins while still reducing or minimizing crackingof paraffins. The catalytic dewaxing conditions can be achieved in partby using a ZSM-48 based catalyst as the dewaxing catalyst. Afterdewaxing, the dewaxed effluent can be separated to form at least a jetboiling range fraction corresponding to the hydrocarbon composition, andone or more lower boiling fractions, such as naphtha fraction(s) orlight ends. While it is possible to also form a diesel boiling rangefraction, it is more difficult to achieve the carbon chain distributionin the hydrocarbon composition when a diesel boiling range fraction (orother higher boiling range fraction) is also formed. This is due to thefact that there is typically some overlap in the boiling ranges forfractions formed by the various types of commercially availableseparators/fractionation towers/distillation columns. Thus, it ispreferred for the hydrocarbon composition to correspond to the “bottoms”or highest boiling fraction formed from the catalytic dewaxing effluent.

In some aspects, the hydrocarbon composition can be formed by processingof a renewable feedstock that has a target compositional profile. Oneaspect of the target compositional profile is to select a feedstock sothat the triglycerides, free fatty acids, and/or other renewable feedsin the feedstock have an elevated content of C₁₇ and C₁₈ chain lengths.Conventional renewable jet fractions typically have a peak in thedistribution of carbon chain lengths for carbon chains containing 11 or12 carbons. For such conventional renewable jet fractions, the contentof C₁₇₊ hydrocarbons in the jet boiling range fraction can be relativelylow, such as 15 wt % or less. By contrast, by using a feedstock with anelevated content of C₁₇ and C₁₈ components, a renewable jet boilingrange product can be formed where 30 wt % or more of the jet boilingrange product corresponds to C₁₇₊ hydrocarbons, or 40 wt % or more, or50 wt % or more, such as up to 70 wt % or possibly still higher. It isnoted that while the content of C₁₇ and C₁₈ hydrocarbons is elevated,the content of C₁₄-C₁₇ hydrocarbons can remain be 50 wt % or less of theweight of the jet boiling range product, or 45 wt % or less, or 40 wt %or less. Additionally, the feedstock can preferably contain a reduced orminimized content of C₁₉₊ carbon chains. Although n-C₁₇ and n-C₁₈paraffins having boiling points above 300° C., branched C₁₇ and C₁₈paraffins (i.e., isoparaffins) have boiling points below 300° C. As aresult, if sufficiently deep isomerization is performed on a feedstock,substantially all of the C₁₇ and C₁₈ paraffins can be retained in a jetboiling range product. By reducing or minimizing the C₁₉₊ paraffinspresent in a feedstock, any C₁₉+ paraffins can either be cracked duringthe isomerization, or can be in sufficiently small quantities that atarget final boiling point of 300° C. can be achieved by blending withother jet boiling range fractions.

In addition to using a feedstock with a target compositional profile,the reaction conditions also contribute to formation the hydrocarboncomposition. In particular, the dewaxing conditions can be selectedwithin a relatively narrow range so that the conditions are sufficientlysevere conditions to cause deep dewaxing of the feed while also beingmild enough to avoid unnecessary cracking of the feedstock. In someaspects, this can allow for production of jet boiling range fractions inyields of 70 wt % or more relative to a weight of the input feed to thedewaxing stage.

Definitions

The “cloud point” of an oil is the temperature below which paraffin waxor other solid substances begin to crystallize or separate from thesolution, imparting a cloudy appearance to the oil when the oil ischilled under prescribed conditions. Cloud point can be determinedaccording to ASTM D7346.

The “freeze point” of a fraction (such as a feed or product) can bedetermined according to ASTM D5972. The “flash point” of a fraction canbe determined according to ASTM D6450.

Unless otherwise specified, the “Liquid Hourly Space Velocity (LHSV)”for a feed or portion of a feed to a reactor is defined as the volume offeed per hour relative to the volume of catalyst in the reactor. In somespecific instances, a liquid hourly space velocity may be specifiedrelative to a specific catalyst within a reactor that contains multiplecatalyst beds.

As used herein, the term “renewable diesel” refers to a hydrocarbonproduct produced from bio-derived feedstocks. Similarly, “renewable jet”refers to a hydrocarbon product produced from bio-derived feedstocks.Examples of typical feedstocks for renewable diesel production includediglycerides, monoglycerides, triglycerides, fatty acid methyl esters(FAME), free fatty acids, and the like, which are often derived fromplant oils, animal fats, or algae oils. Relatedly, the term “bio-diesel”generally refers to fatty acid methyl esters or FAME.

In this discussion, a “Cx” hydrocarbon refers to a hydrocarbon compoundthat includes “x” number of carbons in the compound. A stream containing“Cx-Cy” hydrocarbons refers to a stream composed of one or morehydrocarbon compounds that includes at least “x” carbons and no morethan “y” carbons in the compound. It is noted that a stream containing“Cx-Cy” hydrocarbons may also include other types of hydrocarbons,unless otherwise specified.

In this discussion, “Tx” refers to the temperature at which a weightfraction “x” of a sample can be boiled or distilled. For example, if 40wt % of a sample has a boiling point of 350° F. or less, the sample canbe described as having a T40 distillation point of 350° F. In thisdiscussion, boiling points can be determined by a convenient methodbased on the boiling range of the sample. This can correspond to ASTMD86. In the event that ASTM D86 cannot be performed on a sample due tothe nature of the sample, ASTM D2887 may be used instead.

In various aspects of the invention, reference may be made to one ormore types of fractions generated during distillation of a feedstock,intermediate product, and/or final product. Such fractions may includenaphtha fractions and distillate fuel fractions. Each of these fractionscan be defined based on a boiling range, such as a boiling range thatincludes at least 80 wt % of the fraction, or at least 90 wt % of thefraction. For example, for naphtha fractions, at least 80 wt % of thefraction, or at least 90 wt % of the fraction, can have a boiling pointin the range of 85° F. (29° C.) to 300° F. (149° C.). It is noted that29° C. roughly corresponds to the boiling point of isopentane, a C5hydrocarbon. Fractions boiling below the naphtha range can sometimes bereferred to as light ends. For a jet boiling range fraction 80 wt % ormore of the fraction, or 90 wt % or more, can have a boiling point inthe range of 149° C. to 300° C.

Another option for specifying various types of boiling ranges can bebased on a combination of T5 (or T10) and T95 (or T90) distillationpoints. For example, in some embodiments, having at least 80 wt % (or atleast 90 wt %) of a fraction boil in the naphtha boiling range cancorrespond to having a T10 distillation point (or T5 distillation point)of 29° C. or more and a T90 distillation point (or T95 distillationpoint) of 149° C. or less. For a jet boiling range fraction, the T10distillation point can be between 149° C. and 205° C., while the T90distillation point can be 300° C. or less. In some aspects, a jetboiling range fraction can also have a final boiling point (as measuredby ASTM D86) of 300° C. or less.

In this discussion, reference may be made to gas or vapor portions of aneffluent or product versus liquid portions of an effluent or product. Inthis discussion, a gas product portion or gas effluent portion refers toan effluent portion or product portion that would be in the gas phase at20° C. and 100 kPa-a. Similarly, a liquid product portion or liquideffluent portion refers to an effluent portion or product portion thatwould be in the liquid phase at 20° C. and 100 kPa-a. In thisdiscussion, when describing the current state of an effluent portion orproduct portion (such as the state of a portion or fraction under theconditions present at the exit from a reaction stage), the effluentportion or product portion is described as being in the gas phase or asbeing in the liquid phase. For example, due to the elevated temperatureand pressure in a hydroprocessing stage (such as a hydrotreating stageor a dewaxing stage), the liquid effluent portion of the hydroprocessingeffluent may be present partially or entirely in the gas phase.

Certain aspects and features are described herein using a set ofnumerical upper limits and a set of numerical lower limits. It should beappreciated that ranges from any lower limit to any upper limit arecontemplated unless otherwise indicated. All numerical values are“about” or “approximately” the indicated value, and account forexperimental errors and variations that would be expected by a personhaving ordinary skill in the art.

In this discussion, if it is necessary to determine the oxygen contentof a sample, the oxygen content can be determined using gaschromatography—atomic emission detection (GC-AED) The basic GC-AEDmethod starts by passing a sample for analysis, such as a deoxygenatedjet boiling range fraction, through a gas chromatography system toseparate the components of the sample. The resulting separation streamfrom the gas chromatograph can then be passed into an atomic emissionspectrometer with plasma-excitation capability, along with an inert(carrier) gas and a carbon-containing gas (such as methane). A plasma isthen formed from the mixture, followed by detection of oxygen in theplasma. Examples of this method are described in U.S. Pat. Nos.6,759,438 and 5,151,371, which are incorporated by reference herein forthe limited purpose of describing the GC-AED analytical technique. Astandard spectrometer for GC-AEI) may be used to monitor oxygenconcentration.

Feedstock

In various aspects, jet boiling range fractions can be formed from anyconvenient type of bio-derived feedstock, where the term “bio-derivedfeedstock” refers to a hydrocarbon feedstock derived from a biologicalraw material source, such as vegetable, animal, fish, and/or algae. Forexample, suitable feedstocks include diglycerides, monoglycerides,triglycerides, fatty acid methyl esters (FAME), free fatty acids, andthe like, derived from plant oils, animal fats, or algae oils. In someaspects, a feedstock can be pretreated to remove metals, gums, and othercontaminants (such as refined, bleached, and deodorized (RBD) gradevegetable oil).

As used herein, the term “vegetable oil” (or “vegetable fat”) refersgenerally to any plant-based material and can include fats/oils derivedfrom plant sources, such as plants of the genus Jatropha. Generally, thebiological sources used for the bio-derived feedstock can includevegetable oils/fats, animal oils/fats, fish oils, pyrolysis oils, and/oralgae lipids/oils, as well as any components of such biological sources.In some embodiments, the biological sources specifically include one ormore types of lipid compounds, where the term “lipid compound” generallyrefers to a biological compound that is insoluble in water, but solublein nonpolar (or fat) solvents. Non-limiting examples of such solventsinclude alcohols, ethers, chloroform, alkyl acetates, benzene, andcombinations thereof.

Major classes of lipids include, but are not necessarily limited to,fatty acids, glycerol-derived lipids (including fats, oils, andphospholipids), sphingosine-derived lipids (including ceramides,cerebrosides, gangliosides, and sphingomyelins), steroids and theirderivatives, terpenes and their derivatives, fat-soluble vitamins,certain aromatic compounds, and long-chain alcohols and waxes. In livingorganisms, lipids generally serve as the basis for cell membranes and asa form of fuel storage. Lipids can also be found conjugated withproteins or carbohydrates, such as in the form of lipoproteins andlipopolysaccharides.

Examples of vegetable oils that can be used according to embodimentsdescribed herein include, but are not limited to, rapeseed (canola) oil,soybean oil, coconut oil, sunflower oil, palm oil, palm kernel oil,peanut oil, linseed oil, tall oil, corn oil, castor oil, jatropha oil,jojoba oil, olive oil, flaxseed oil, camelina oil, safflower oil,babassu oil, tallow oil, and rice bran oil. According to embodimentsdescribed herein, vegetable oils can also include processed vegetableoil material. Non-limiting examples of processed vegetable oil materialinclude fatty acids and fatty acid alkyl esters. Alkyl esters typicallyinclude C₁-C₅ alkyl esters. One or more of methyl, ethyl, and propylesters are preferred.

Examples of animal fats that can be used according to embodimentsdescribed herein include, but are not limited to, beef fat (tallow), hogfat (lard), turkey fat, fish fat/oil, and chicken fat. The animal fatscan be obtained from any suitable source, including restaurants and meatproduction facilities. According to embodiments described herein, animalfats can also include processed animal fat material. Non-limitingexamples of processed animal fat material include fatty acids and fattyacid alkyl esters. Alkyl esters typically include C₁-C₅ alkyl esters.One or more of methyl, ethyl, and propyl esters are preferred.

Algae oils or lipids are typically contained in algae in the form ofmembrane components, storage products, and metabolites. Certain algalstrains, particularly microalgae such as diatoms and cyanobacteria,contain proportionally high levels of lipids. Algal sources for thealgae oils can contain varying amounts, e.g., from 2 wt % to 40 wt % oflipids, based on the total weight of the biomass itself. Algal sourcesfor algae oils include, but are not limited to, unicellular andmulticellular algae. Examples of such algae include rhodophyte,chlorophyte, heterokontophyte, tribophyte, glaucophyte,chlorarachniophyte, euglenoid, haptophyte, cryptomonad, dinoflagellum,phytoplankton, and the like, and combinations thereof. In oneembodiment, algae can be of the classes Chlorophyceae and/or Haptophyta.Specific species can include, but are not limited to, Neochlorisoleoabundans, Scenedesmus dimorphus, Euglena gracilis, Phaeodactylumtricornutum, Pleurochrysis carterae, Prymnesium parvum, Tetraselmischui, and Chlamydomonas reinhardtii.

Moreover, according to embodiments described herein, the bio-derivedfeedstock can include any feedstock that consists primarily oftriglycerides and free fatty acids (FFAs). The triglycerides and FFAstypically contain aliphatic hydrocarbon chains in their structure havingfrom 8 to 36 carbons, or preferably from 10 to 26 carbons, or mostpreferably from 14 to 22 carbons. Types of triglycerides can bedetermined according to their fatty acid constituents. The fatty acidconstituents can be readily determined using Gas Chromatography (GC)analysis. This analysis involves extracting the fat or oil, saponifying(hydrolyzing) the fat or oil, preparing an alkyl (e.g., methyl) ester ofthe saponified fat or oil, and determining the type of (methyl) esterusing GC analysis. In one embodiment, a majority (i.e., greater than50%) of the triglyceride present in the lipid material can consist ofC₁₀ to C₂₆ fatty acid constituents, based on the total triglyceridepresent in the lipid material.

Furthermore, a triglyceride is a molecule having a structuresubstantially identical to the reaction product of glycerol and threefatty acids. Thus, although a triglyceride is described herein asconsisting of fatty acids, it should be understood that the fatty acidcomponent does not necessarily contain a carboxylic acid hydrogen. Inone embodiment, a majority of triglycerides present in the biocomponentfeed can preferably consist of C₁₂ to C₁₈ fatty acid constituents, basedon the total triglyceride content. Other types of feeds that are derivedfrom biological raw material components can include fatty acid esters,such as fatty acid alkyl esters (e.g., FAME and/or FAEE).

In some aspects, the feedstock can correspond to a feedstock thatcontains a reduced or minimized content of C₁₉₊ carbon chains (i.e., areduced or minimized content of glycerides and/or fatty acid estersand/or free fatty acids that have carbon chains of 19 carbons or more).By reducing or minimizing the amount of C₁₉₊ carbon chains in thefeedstock, the number of C₁₉ paraffins in the resulting product are alsoreduced or minimized. This can be beneficial for forming a jet boilingrange fraction without using a separation to remove diesel boiling rangecomponents. In such aspects, the feedstock can include 5.0 wt % or lessof C₁₉₊ carbon chains, or 3.0 wt % or less, or 1.0 wt % or less, or 0.1wt % or less, such as down to having substantially no C₁₉₊ carbon chains(0.01 wt % or less). It is noted that a diglyceride contains twoseparate carbon chains while a triglyceride includes three separatecarbon chains. Thus, in feedstocks containing diglycerides and/ortriglycerides, the weight of each carbon chain in a triglyceride isconsidered separately. For example, if a triglyceride contains one C₁₉carbon chain and two C₁₈ carbon chains, only the weight of the C₁₉carbon chain would be considered (and not the weight of thetriglyceride) when calculating the weight of C₁₉₊ carbon chains in thefeedstock.

In some further aspects, the feedstock can include 50 wt % or more ofC₁₇-C₁₈ carbon chains, or 60 wt % or more, or 70 wt % or more, or 80 wt% or more, or 90 wt % or more, such as up to substantially all of thefeedstock corresponding to C₁₇-C₁₈ carbon chains. In such aspects,having a feedstock with an elevated content of C₁₇-C₁₈ carbon chains canbe beneficial for forming a high density, high energy content jetboiling range fraction while still having final boiling point for thefraction that is below 300° C.

Hydrotreatment for Hydrodeoxygenation

In various aspects, the bio-derived feedstock can be exposed tohydrotreatment conditions for deoxygenation of the feedstock. Thehydrotreatment can be performed in any convenient type of hydrotreatmentreactor, such as fixed bed or trickle-bed reactor.

A hydrotreatment catalyst can contain at least one of Group VIB and/orGroup VIII metals, optionally on a support such as alumina or silica.Examples include, but are not limited to, NiMo, CoMo, and NiW supportedcatalysts. In some embodiments, NiMo and Mo on alumina are preferredcatalysts.

Effective hydrotreatment conditions can be selected according to thedetails of each specific implementation. In a preferred embodiment, thehydrotreatment conditions include a total pressure of 200 psig to 2000psig (˜1.4 MPa-g to 14 MPa-g), a weighted average bed temperature (WABT)of 260° C. (i.e., 500° F.) to 400° C. (i.e., 752° F.), a hydrogen-richtreat gas rate of 200 standard cubic feet of gas per barrel of feedstock(scf/bbl) to 10,000 scf/bbl (˜34 Nm³/m³ to 1700 Nm³/m³), and a liquidhourly space velocity (LHSV) of about 0.1 hr⁻¹ to about 10.0 hr⁻¹. Insome aspects, the oxygen content of the resulting hydrotreated feedstockis less than about 0.4 wt % or less than about 0.1 wt % such as down tohaving substantially no oxygen content (less than 1.0 wppm). Withoutbeing bound by any particular theory, it is believed that residualoxygenates in the hydrotreated feedstock convert to H₂O and CO duringthe deep dewaxing process, thus inhibiting the isomerization activity ofthe isomerization/dewaxing catalyst.

Optionally, a hydrotreatment reactor can be used that operates at arelatively low total pressure values, such as total pressures of about200 psig (1.4 MPag) to about 800 psig (5.5 MPag). For example, thepressure in a stage in the hydrotreatment reactor can be at least about200 psig (1.4 MPag), or at least about 300 psig (2.1 MPag), or at leastabout 400 psig (2.8 MPag), or at least about 450 psig (3.1 MPag). Thepressure in a stage in the hydrotreatment reactor can be about 800 psig(5.5 MPag) or less, or about 700 psig (4.8 MPag) or less, or about 600psig (4.1 MPa) or less.

In some embodiments, the sulfur and nitrogen contents of the feedstockmay be advantageously reduced during the hydrotreatment process. Forexample, in some embodiments, the hydrotreatment process reduces thesulfur content of the feedstock to a suitable level, such as, forexample, less than about 100 weight parts per million (wppm), less thanabout 50 wppm, less than about 30 wppm, less than about 25 wppm, lessthan about 20 wppm, less than about 15 wppm, or less than about 10 wppm,such as down to 0.1 wppm or possibly still lower. With regard tonitrogen, in some embodiments, the hydrotreatment process reduces thenitrogen content of the feedstock to a suitable level, such as, forexample, about 30 wppm or less, about 25 wppm or less, about 20 wppm orless, about 15 wppm or less, about 10 wppm or less, about 5 wppm orless, or about 3 wppm or less, such as down to 0.1 wppm or possiblystill lower.

In various embodiments, the hydrotreatment process is also used todeoxygenate the feedstock. Deoxygenating the feedstock may help to avoidproblems with catalyst poisoning or deactivation due to the creation ofwater (H₂O) or carbon oxides (e.g., CO and CO₂) during catalyticdewaxing. Accordingly, the hydrotreatment process can be used to remove,for example, at least 90%, at least 95%, at least 98%, at least 99%, atleast 99.5%, at least 99.9%, or completely (measurably) all of theoxygen present in the deoxygenated feedstock. Alternatively, theoxygenate level of the feedstock can be reduced to, for example, 0.1 wt% or less, 0.05 wt % or less, 0.03 wt % or less, 0.02 wt % or less, 0.01wt % or less, 0.005 wt % or less, 0.003 wt % or less, 0.002 wt % orless, or 0.001 wt % (10 wppm) or less, such as down to havingsubstantially no oxygen content remaining in the deoxygenated feedstock(less than 1.0 wppm).

In aspects where the feedstock for hydrotreatment includes asufficiently high content of components having a C₁₇₊ carbon chain, theresulting deoxygenated effluent can have a correspondingly high contentof C₁₇₊ n-paraffins. In such aspects, the liquid portion of thedeoxygenated effluent can contain 50 wt % or more of C₁₇₊ n-paraffins,or 60 wt % or more, or 70 wt % or more, or 80 wt % or more, such as upto 95 wt % or possibly still higher.

Separation Between Hydrotreatment and Catalytic Dewaxing

In various aspects, a separation stage can be used to separate outimpurities from the hydrotreated feedstock prior to passing thehydrotreated feedstock to the isomerization/dewaxing reactor. Inparticular, the separation process minimizes the amount of H₂O and COthat is slipped into the isomerization/dewaxing reactor by separatingthe gas and liquid phases within the hydrotreated feedstock. While aninterstage stripper is preferred for this purpose, any suitableseparation device can be used, such as, for example, any suitable typeof separator or fractionator that is configured to separate gas-phaseproducts from liquid-phase products.

In some aspects, the gas phase exiting the separation device can berecycled and combined with the hydrogen-rich treat gas that is fed intothe hydrotreatment reactor. In addition, in various aspects, a portionof the liquid phase exiting the separation stage can be recycled backinto the hydrotreatment reactor to provide improved heat release controlfor the hydrotreatment reactor.

Catalytic Dewaxing

In various aspects, at least a portion of the deoxygenated effluent isthen exposed to catalyst based on the zeolite ZSM-48. ZSM-48 is a10-member ring, one-dimensional zeotype of the MRE framework type.ZSM-48 based catalysts have a high selectivity for isomerization ofparaffinic feeds relative to cracking. Thus, a ZSM-48 based catalyst canprovide substantially complete isomerization of a paraffinic feed (suchas a deoxygenated bio-derived feed) while reducing or minimizingcracking of the paraffinic carbon chains. In some aspects, the catalystcan consist essentially of ZSM-48, any optional binder, and ahydrogenation metal, so that less than 1.0 wt % or less of the catalyst(relative to the weight of the catalyst) corresponds to a zeotypestructure different from an MRE framework structure, or less than 0.1 wt%, such as down to having substantially no zeotype content differentfrom an MRE framework structure (0.01 wt % or less). In some aspects,the ZSM-48 in the catalyst can have a silica to alumina ratio of 90:1 orless, or 75:1 or less, such as down to 60:1 or possibly still lower.

Optionally but preferably, the dewaxing catalyst can include a binderfor the ZSM-48, such as alumina, titania, silica, silica-alumina,zirconia, or a combination thereof, for example alumina and/or titaniaor silica and/or zirconia and/or titania. The relative amount of ZSM-48and binder can be any convenient amount. In some aspects where a binderis present, the catalyst can include 1.0 wt % to 85 wt % of a binderand/or can include 15 wt % to 99 wt % of ZSM-48.

In addition to ZSM-48 and optional binder, the dewaxing catalyst canalso include at least one metal hydrogenation component selected fromPd, Pt, or a combination thereof. When a metal hydrogenation componentis present, the dewaxing catalyst can include 0.1 wt % to 10 wt % of thePt, Pd, or combination thereof, or 0.1 wt % to 5.0 wt %, or 0.5 wt % to10 wt %, or 0.5 wt % to 5.0 wt %, or 1.0 wt % to 10 wt %, or 1.0 wt % to5.0 wt %.

The isomerization/dewaxing reactor may include any suitable type ofreactor arranged in any suitable configuration. For example, in someembodiments, the isomerization/dewaxing reactor is a fixed-bed adiabaticreactor or a trickle-bed reactor that is loaded with the ZSM-48-basedisomerization/dewaxing catalyst.

The deoxygenated feedstock (or at least a portion thereof, such as theliquid product portion) is exposed to the ZSM-48 basedisomerization/dewaxing catalyst under effective isomerization/dewaxingconditions. The effective conditions are selected to provide sufficientseverity so that substantially complete dewaxing occurs for then-paraffins in the deoxygenated effluent while still reducing orminimizing cracking. This allows a substantial portion of C₁₇-C₁₈hydrocarbons to be retained within a jet boiling range composition(based on substantially complete isomerization) while avoiding“overcracking” that would convert excess amounts of C₁₇-C₁₈ hydrocarbonsin the deoxygenated effluent into smaller compounds. In various aspects,the isomerization/dewaxing conditions include a total pressure of 200psig (1.4 MPa-g) to 2000 psig (14 MPa-g), a WABT of 300° C. to 350° C.,a treat gas rate of 200 scf/bbl to 10,000 scf/bbl (˜34 Nm³/m³ to 1700Nm³/m³), and an LHSV of 1.0 hr⁻¹ to about 8.0 hr⁻¹ (relative to a volumeof the dewaxing catalyst).

In some aspects, the severity of the reaction conditions can becharacterized based on a severity index. The severity index is aninteger that can be calculated in the following manner. For the weightedaverage bed temperature, for each 10° C. greater than 305° C., theseverity index is increased by one. For pressure, for each 200 psi (0.7MPa) that the pressure is greater than 400 psig (2.8 MPa-g), theseverity index is increased by one. For space velocity, for each 1.0hr⁻¹ that the LHSV is less than 5.0 hr⁻¹, the severity index isincreased by one. A severity index of two or less corresponds toconditions that are likely insufficient to achieve substantiallycomplete dewaxing. A severity index of 10 or more corresponds toconditions that are likely to result in excess cracking of thedeoxygenated effluent. The severity index is designed to measureseverity within the effective reaction conditions described above forisomerization/dewaxing. Thus, even though some combinations withtemperatures of 350° C. or higher could potentially have a severityindex of less than 10, such conditions are not preferred when avoidingcracking. In some aspects, the severity index can be 3 to 9, or 3 to 7.

In various aspects, after hydrotreating and catalytic dewaxing, theoxygen content of the liquid dewaxing effluent can be less than 10 wppm,or less than 2.0 wppm, such as down to having substantially no oxygencontent (1.0 wppm or less).

Separation of the Dewaxing Effluent

In some aspects where a diesel boiling range product does not need to beseparated from the dewaxing effluent, a simple separation scheme can beused to recover the jet boiling range product from the dewaxingeffluent. For example, a separation can be performed to separate thedewaxing effluent into a jet boiling range fraction and a lower boilingrange fraction. The lower boiling range fraction can optionally undergofurther separations to form at least one naphtha fraction and one ormore light ends fractions. However, such additional separations on thelower boiling portion are not needed to recover the jet boiling rangeproduct fraction.

In other aspects, if the input feed to the dewaxing stage includes asufficiently high content of C₁₉₊ hydrocarbons, the separation of thedewaxing effluent can further include formation of a diesel boilingrange fraction. In such aspects where a diesel boiling range fraction isformed, at least a portion of the diesel boiling range fraction canoptionally be recycled back to the hydrotreatment stage and/or thedewaxing stage. Such recycle can allow for additional opportunity forconversion of C₁₉₊ hydrocarbons into jet boiling range hydrocarbons thatcan be incorporated into the jet boiling range hydrocarbon composition.Any portion of the diesel boiling range fraction that is not recycledcan be used for any convenient purpose. For example, such a dieselboiling range fraction represents a highly isomerized paraffinic dieselfraction. Such a diesel boiling range fraction can have a favorably highcetane rating as well as favorable cold flow properties. As a result,such a diesel boiling range fraction can be used as a diesel fuel and/oras a blend component for a diesel fuel, including arctic or winterdiesel.

Properties of Jet Boiling Range Product

In various aspects, the jet boiling range product can have one or moreof the following properties. The jet boiling range product can have aT10 distillation point of 205° C. or less and a final boiling point of310° C. or less, or 300° C. or less. The jet boiling range product canhave a density at 15° C. of 760 kg/m³ or more, or 765 kg/m³ or more, or768 kg/m³ or more, or 770 kg/m³ or more, such as up to 772 kg/m³ orpossibly still higher. The jet boiling range product can have a freezepoint of −40° C. or less, or −47° C. or less, or −50° C. or less, suchas down to −100° C. or possibly still lower. The jet boiling rangeproduct can have a flash point of 38° C. or higher, or 40° C. or higher,or 45° C. or higher, such as up to 80° C. or possibly still higher. Theyield of jet boiling range product can be 70 wt % or more relative tothe weight of the input feed to the dewaxing stage, or 75 wt % or more,or 80 wt % or more, or 86 wt % or more, such as up to 92 wt % orpossibly still higher. In other aspects, such as some aspects whereadditional cracking is performed and/or where diesel recycle isperformed, the yield can be lower, such as 55 wt % or more, or 60 wt %or more or 65 wt % or more.

In some aspects, the resulting jet boiling range product can have anunexpectedly high content of C₁₇-C₁₈ hydrocarbons. In such aspects, thejet boiling range fraction can contain 30 wt % or more of C₁₇-C₁₈hydrocarbons, or 40 wt % or more, or 50 wt % or more, or 60 wt % ormore, such as up to 80 wt % or possibly still higher. Additionally oralternately, the jet boiling range fraction can contain 45 wt % or lessof C₁₄-C₁₇ hydrocarbons, or 40 wt % or less, or 35 wt % or less, such asdown to 25 wt % or possibly still lower.

In addition to the above, in some aspects, the jet boiling rangefraction can satisfy one or more of the following specifications fromASTM D7566 (Annex 2). Examples of property specifications and/or typicalproperties include a total acidity of 0.015 mg KOH/g or less, a sulfurcontent of 15 wppm or less, a freezing point of −40° C. or less, a flashpoint of 38° C. or higher, a T10 distillation point of 205° C. or less,and/or a final boiling point of 300° C. or less. Another example of aproperty specification is a specification for a maximum pressureincrease during a thermal stability test at 325° C. (according to ASTMD3241), such as a maximum pressure increase of 25 mm Hg.

It is noted that due to the bio-derived nature of the jet boiling rangefraction, the sulfur content of the jet boiling range can be relativelylow, such as being substantially free of sulfur. Thus, in some aspects,the sulfur content of the jet boiling range fraction can be 100 wppm orless, or 10 wppm or less, such as down to having substantially no sulfurcontent (0.1 wppm or less). Similarly, due to the hydrodeoxygenation anddewaxing steps, the oxygen content of the jet boiling range fraction canbe relatively low, such as substantially free of oxygen. Thus, in someaspects, the oxygen content of the jet boiling range fraction can be 100wppm or less, or 10 wppm or less, or 5.0 wppm or less, or 1.0 wppm orless, such as down to having substantially no oxygen content (0.1 wppmor less).

Configuration Example

FIG. 1 shows an example of a reaction system 100 for producing arenewable jet boiling range product. As shown in FIG. 1 , a bio-derivedfeedstock 102 is introduced into a hydrotreatment reactor 104. A firstportion 106 of a hydrogen-rich treat gas stream 108 is also introducedinto the hydrotreatment reactor 104. It will be appreciated by one ofskill in the art that, while the hydrogen-rich treat gas stream 108 isdepicted in FIG. 1 as entering the top of the hydrotreatment reactor104, this is for the sake of simplicity only. In operation, thehydrogen-rich treat gas stream 108 may be introduced into thehydrotreatment reactor 104 at various locations, such as at quenchlocations corresponding to each reactor bed.

The bio-derived feedstock 102 is then exposed to effectivehydrotreatment conditions in the hydrotreatment reactor 104 in thepresence of one or more catalyst beds that contain a suitablehydrotreating catalyst, resulting in the generation of a hydrotreatedfeedstock 110. At least a portion of the hydrotreated feedstock 110exiting the hydrotreatment reactor is then introduced into a separationdevice 112, such as an interstage stripper. Within the separation device112, a gas product portion is separated from liquid product portion. Thegas product portion is then output as a first overhead stream 114 thatcan optionally be recycled and combined with the first portion 106 ofthe hydrogen-rich treat gas stream 108 entering the hydrotreatmentreactor 104. In addition, the liquid product portion corresponds toliquid stream 116.

As shown in FIG. 1 , some portion of the liquid stream 116 may(optionally) be recycled back into the hydrotreatment reactor 104 toprovide heat release control for the hydrotreatment reactor 104. Therest of the liquid stream 116 (or the entirety of the liquid stream 116for embodiments that do not include liquid recycling) is then introducedinto an isomerization/dewaxing reactor 118. A second portion 120 of thehydrogen-rich treat gas stream 108 is also introduced into theisomerization/dewaxing reactor 118. It will be appreciated by one ofskill in the art that, while the hydrogen-rich treat gas stream 108 isdepicted in FIG. 1 as entering the top of the isomerization/dewaxingreactor 118, this is for the sake of simplicity only. In operation, thehydrogen-rich treat gas stream 108 may be introduced into theisomerization/dewaxing reactor 118 at various locations, such as at thequench locations corresponding to each reactor bed.

Within the isomerization/dewaxing reactor 118, the liquid stream 116 isexposed to suitable catalytic isomerization/dewaxing conditions in thepresence of one or more catalyst beds that contain a ZSM-48-basedisomerization/dewaxing catalyst, resulting in the generation of anisomerized product stream 122. Finally, the isomerized product stream122 exiting the isomerization/dewaxing reactor 118 is flowed through aseparator 124. Within the separator 124, the isomerized product stream122 is separated into a lower boiling fraction 126 and a jet boilingrange product 130. Optionally, a portion of the overhead gas 128 fromthe isomerization/dewaxing reactor 118 can be in a manner similar tofirst overhead stream 114.

FIG. 2 shows another example of a reaction system that can be used forforming a hydrocarbon composition as described herein. In FIG. 2 , thereaction system 200 includes a modified separation stage 224 that allowsfor formation of at least three products from isomerized product stream122. The three products can include a jet boiling range product 230, alower boiling fraction 126, and a diesel boiling range fraction 240.Optionally, a portion 244 of diesel boiling range fraction 240 can berecycled for use as part of the input flow to hydrotreatment reactor 104and/or as part of the input flow for isomerization/dewaxing reactor 118.

The schematic views of the reaction systems in the figures are notintended to indicate that the reaction systems are required to includeall of the components shown in the figures, or that the reaction systemsare limited to only the components shown in the figures. Rather, anynumber of components may be omitted from the reaction systems, or addedto the reaction systems, depending on the details of the specificimplementation. For example, in some embodiments, the separation device112 in FIG. 1 is omitted from the reaction system 100, and thehydrotreated feedstock is passed directly from the hydrotreatmentreactor 104 to the isomerization/dewaxing reactor 118. Moreover, in someembodiments, multiple hydrotreatment reactors and/or multipleisomerization/dewaxing reactors are included within a reaction system.As still another example, while the reaction system 100 in FIG. 1 isdepicted as including separate hydrotreatment and isomerization/dewaxingreactors 104 and 118, respectively, one of skill in the art willappreciate that the hydrotreatment and isomerization/dewaxing stages canalternatively be combined into a single reactor without changing theoverall technical effect of the reaction system 100.

EXAMPLES

A series of dewaxing processes were performed in a pilot scale reactorusing a model feed. The pilot scale reactor was a down flow reactor. APt/ZSM-48 bound catalyst was used that included 0.6 wt % Pt relative tothe weight of the catalyst. The ZSM-48 had a silica to alumina ratio ofroughly 70:1. The model feed was a blend n-paraffins corresponding toC₁₅-C₁₈ paraffins, and therefore corresponds to a feed that has alreadybeen deoxygenated. The model feed is believed to be representative of atype of renewable diesel. The properties of the feed are shown in Table1.

TABLE 1 Feedstock Characterization Method Description Unit 1747 Hydrogenmass % 14.92 AMS1208 Nitrogen ppm <2.5 D2622 Sulfur ppm <5 B3942Calculated density 15° C. g/cm³ 0.7887 D2887 .5 PCT OFF - SIMDIS ° F./°C. 516/269 D2887 10 PCT OFF - SIMDIS ° F./° C. 575/301 D2887 20 PCTOFF - SIMDIS ° F./° C. 579/304 D2887 30 PCT OFF - SIMDIS ° F./° C.585/307 D2887 40 PCT OFF - SIMDIS ° F./° C. 601/316 D2887 50 PCT OFF -SIMDIS ° F./° C. 605/318 D2887 60 PCT OFF - SIMDIS ° F./° C. 607/320D2887 70 PCT OFF - SIMDIS ° F./° C. 609/321 D2887 80 PCT OFF - SIMDIS °F./° C. 611/322 D2887 90 PCT OFF - SIMDIS ° F./° C. 612/322 D2887 99.5PCT OFF - SIMDIS ° F./° C. 639/337 D7346 Cloud point ° C. 25 M738 Waterppm 44

It is noted that the boiling point of n-C₁₆ paraffin is 548° F. (287°C.) and the boiling point of n-C₁₇ paraffin is 576° F. (302° C.). Thus,based on the fractional weight distillation values in Table 1, the feedin Table 1 includes roughly 90 wt % or more of C₁₇₊ n-paraffins, asindicated by the T10 distillation point of 574° F. (301° C.).Additionally, the boiling point of n-C₁₈ paraffin is 603° F. (317° C.)while the boiling point of n-C₁₉ paraffin is 624° F. (329° C.). Asindicated by the T90 distillation point of 612.3° F. (322° C.) and theT99.5 distillation point of 638.8° F. (337° C.), the model feed includedroughly 1.0 wt % of C₁₉₊ n-paraffins.

Example 1

The feed from Table 1 was exposed to the Pt/ZSM-48 catalyst in the pilotscale reactor with the following conditions: pressure 610 psig (4.2MPa-g), LHSV 4 hr⁻¹, temperature 640° F. (338° C.) and hydrogen treatgas to feed ratio 2000 scf/b (˜340 Nm³/m³). This corresponds to aseverity index of 6. Table 2 shows results from characterization of thejet boiling range fraction. It is noted that the jet boiling rangefraction corresponds to the “bottoms” from the separation, as there isnot a separate diesel fraction. The properties meet the ASTM D7566(Annex 2) specifications.

TABLE 2 Properties of Jet Boiling Range Fraction ASTM D7566 MethodDescription Unit Specification Sample 1 D5972 Freezing Point ° C. −40max −66 D6450 Flash Point ° C. 38 min 43 G22 Density, 15° C. kg/m3730-772 769 D86 T10 ° C. 205 max 171 D86 T90 ° C. Report 281 D86 Finalboiling point ° C. 300 283 D86 T90-T10 22 min 110 % product with 17 andwt. % 55 more carbon atoms per molecule % product with 14-17 wt. % 31carbon atoms per molecule

As shown in Table 2, the jet boiling range fraction separated from thedewaxing effluent meets a variety of properties that are desirable for ajet fuel and/or jet fuel blending component. The final boiling point isless than 300° C., the freezing point is less than −60° C., and theflash point is greater than 40° C. Additionally, more than 50 wt % ofthe jet boiling range fraction corresponds to C₁₇₊ hydrocarbons, whileless than 35 wt % of the fraction corresponds to C₁₄-C₁₇ hydrocarbons.This unusual carbon chain distribution contributes to the high densityfor the jet boiling range fraction.

Example 2

In another processing run, the feed from Table 1 was exposed to thePt/ZSM-48 catalyst in the pilot scale reactor with the followingconditions: pressure 605 psig (4.1 MPa-g), LHSV 4 hr⁻¹, temperature 620°F. (327° C.) and hydrogen treat gas to feed ratio 2000 scf/b (˜340Nm³/m³). This corresponds to a severity index of 5. Table 3 shows theproduct yields relative to the weight of the feed.

TABLE 3 Product yield from dewaxing Yields Hydrogen consumption, 134scf/b C₁, wt % 0.03 C₂, wt % 0.07 C₃, wt % 0.82 C₄, wt % 2.28 Naphtha,wt % 10.0 Jet, wt % 86.7

As shown in Table 3, the yield of the jet boiling range product wasgreater than 85 wt % relative to the input feed to the dewaxing reactor.It is noted that the jet boiling range fraction corresponds to the“bottoms” from the separation, as there is not a separate dieselfraction. Table 4 shows properties (D86 distillation, flash and freezingpoint) of the resulting jet boiling range product. The properties meetthe ASTM D7566 (Annex 2) specifications.

TABLE 4 Properties of Jet Boiling Range Fraction ASTM D7566 MethodDescription Unit Jet Product Specification D86 .5 PCT OFF ° F./° C.293/145 D86 10 PCT OFF ° F./° C. 341/172 <401 Max D86 20 PCT OFF ° F./°C. 374/190 D86 30 PCT OFF ° F./° C. 441/227 D86 40 PCT OFF ° F./° C.485/252 D86 50 PCT OFF ° F./° C. 508/264 D86 60 PCT OFF ° F./° C.520/271 D86 70 PCT OFF ° F./° C. 527/275 D86 80 PCT OFF ° F./° C.532/278 D86 90 PCT OFF ° F./° C. 536/280 D86 99.5 PCT OFF ° F./° C.537/281 <300 D5972 Freezing Point ° C. −43 <−40 D6450 Flash Point ° C. 53  >38

As shown in Table 4, the jet boiling range fraction separated from thedewaxing effluent meets a variety of properties that are desirable for ajet fuel and/or jet fuel blending component. The final boiling point isless than 300° C., the freezing point is less than −40° C., and theflash point is greater than 50° C.

In addition to the characterization shown in Table 4, the carbon chainlengths for the paraffins in the jet fuel boiling range product werecharacterized. Table 5 shows additional characterization values for thejet boiling range fraction.

TABLE 5 Additional Properties ASTM D7566 Method Description UnitSpecification Sample 2 G22 Density, 15° C. kg/m3 730-772 772 D86 T10 °C. 205 max 190 D86 T90 ° C. 281 D86 Final boiling point ° C. 300 284 D86T90-T10  22 min 91 NOISE % product with 17 and wt. % 62 more carbonatoms per molecule % product with 14-17 wt. % 35 carbon atoms permolecule

For the jet boiling range fraction shown in Table 5, 62 wt % of thehydrocarbons in the fraction corresponded to C₁₇ and C₁₈ hydrocarbons.Based on the boiling range, substantially all of the C₁₇ and C₁₈hydrocarbons corresponded to isoparaffins. Additionally, the weightpercentage of C₁₄-C₁₇ hydrocarbons in the jet fuel boiling rangefraction shown in Table 5 was only 35 wt %. This represents anunexpected distribution of carbon chains within a jet fuel and/or jetfuel blend component. Due in part to the high percentage of C₁₇ and C₁₈hydrocarbons, the density of the jet boiling range fraction shown inTable 5 was 772 kg/m³.

Comparative Example 3

In still another processing run, the feed from Table 1 was exposed tothe Pt/ZSM-48 catalyst in the pilot scale reactor with the followingconditions: pressure 600 psig (4.1 MPa-g), LHSV 4 hr⁻¹, temperature 595°F. (313° C.) and hydrogen treat gas to feed ratio 2000 scf/b (˜340Nm³/m³). In part due to the lower temperature, this corresponds to aseverity index of 3. As a result, the severity was too low to achievedeep dewaxing. Due to the lower severity, a substantial portion ofn-paraffins remained in the dewaxed effluent, so an additionalseparation was performed to separate a diesel boiling range fractionfrom the jet boiling range fraction. Thus, these conditions would not besuitable for forming a jet boiling range fraction without having aseparation to remove heavier hydrocarbons. Table 6 shows properties ofthe resulting jet boiling range fraction.

TABLE 6 Properties of Jet Boiling Range Fraction ASTM D7566 MethodDescription Unit Specification Sample 1 D7346 Cloud Point ° C. −51 G22Density, 15° C. kg/m3 730-772 759 D86 T10 ° C. 205 max 164 D86 T90 ° C.Report 267 D86 Final boiling point ° C. 300 275 D86 T90-T10  22 min 103% product with 17 and wt. % 17 more carbon atoms per molecule

Due to the lack of full isomerization of the C₁₇ and C₁₈ paraffins inthe input feed to the dewaxing stage, the jet yield was less than 80 wt%. Additionally, the density of the resulting jet boiling range fractionwas lower, at 759 kg/m³. The distribution of carbon chain lengths in theresulting jet fraction was also substantially different, as only 17 wt %of the jet fraction corresponded to C₁₇ and C₁₈ hydrocarbons.

Additional Embodiments

Embodiment 1. A jet boiling range composition, comprising 40 wt % ormore of C₁₇-C₁₈ hydrocarbons and 45 wt % or less of C₁₄-C₁₇hydrocarbons, the composition having a T10 distillation point of 205° C.or less, a T90 distillation point of 300° C. or less, a density of 765kg/m³ or more, a flash point of 38° C. or more, and a freeze point of−40° C. or less, the composition comprising 90 wt % or more ofisoparaffins.

Embodiment 2. The composition of Embodiment 1, wherein the compositioncomprises a final boiling point of 300° C. or less.

Embodiment 3. The composition of any of the above embodiments, whereinthe composition comprises 50 wt % or more of C₁₇-C₁₈ hydrocarbons.

Embodiment 4. The composition of any of the above embodiments, whereinthe composition comprises 45 wt % or less of C₁₄-C₁₇ hydrocarbons, orwherein the composition comprises 5.0 wt % or less of C₁₉₊ hydrocarbons,or a combination thereof.

Embodiment 5. The composition of any of the above embodiments, whereinthe composition comprises 1.0 wppm or less of oxygen, or wherein thecomposition comprises 10 wppm or less of sulfur, or a combinationthereof.

Embodiment 6. The composition of any of the above embodiments, whereinthe composition comprises a renewable jet boiling range composition.

Embodiment 7. A method for producing a jet boiling range fraction,according to any of Embodiments 1 to 6, the method comprising:contacting a bio-derived feedstock with a hydrotreatment catalyst undereffective hydrotreatment conditions to produce a deoxygenated effluentcomprising a deoxygenated liquid fraction, the bio-derived feedstockcomprising 70 wt % or more of C₁₇₊ carbon chains; contacting at least aportion of the deoxygenated liquid fraction with a dewaxing catalystcomprising ZSM-48 and Pt, Pd, or a combination thereof under effectivedewaxing conditions to produce an isomerized effluent, the effectivedewaxing conditions comprising a weighted average bed temperature of300° C. to 350° C., a pressure of 1.4 MPa-g to 14 MPa-g, and a LHSV of1.0 hr⁻¹ to 8.0 hr⁻¹ relative to a volume of dewaxing catalyst; andseparating the isomerized effluent to form the jet boiling rangefraction and one or more lower boiling fractions.

Embodiment 8. The method of Embodiment 7, wherein a yield of the jetboiling range fraction is 70 wt % or more relative to a weight of the atleast a portion of the deoxygenated liquid fraction.

Embodiment 9. The method of Embodiment 7 or 8, wherein the bio-derivedfeedstock comprises 5.0 wt % or less of C₁₉₊ carbon chains.

Embodiment 10. The method of any of Embodiments 7 to 9, wherein the atleast a portion of the deoxygenated effluent comprises 80 wt % or moreof C₁₇₊ n-paraffins.

Embodiment 11. The method of any of Embodiments 7 to 10, wherein theeffective dewaxing conditions comprise a severity index of 3 to 9.

Embodiment 12. The method of any of Embodiments 7 to 11, whereincontacting the bio-derived feedstock with a hydrotreatment catalystfurther comprises contacting at least a portion of the deoxygenatedeffluent with the hydrotreatment catalyst.

Embodiment 13. The method of any of Embodiments 7 to 12, whereinseparating the isomerized effluent further comprises forming a dieselboiling range fraction, and wherein contacting at least a portion of thedeoxygenated liquid fraction with a dewaxing catalyst comprisescontacting at least a portion of the diesel boiling range fraction withthe catalyst.

Embodiment 14. The method of any of Embodiments 7 to 13, furthercomprising separating the deoxygenated liquid fraction from thedeoxygenated effluent.

Embodiment 15. The method of any of Embodiments 7 to 14, wherein thedewaxing catalyst comprises 0.1 wt % to 2.0 wt % of Pt, Pd, or acombination thereof, relative to a weight of the dewaxing catalyst

While the present invention has been described and illustrated byreference to particular embodiments, those of ordinary skill in the artwill appreciate that the invention lends itself to variations notnecessarily illustrated herein. For this reason, then, reference shouldbe made solely to the appended claims for purposes of determining thetrue scope of the present invention.

What is claimed is:
 1. A jet boiling range composition, comprising 40 wt% or more of C₁₇-C₁₈ hydrocarbons and 45 wt % or less of C₁₄-C₁₇hydrocarbons, the composition having a T10 distillation point of 205° C.or less, a T90 distillation point of 300° C. or less, a density of 765kg/m³ or more, a flash point of 38° C. or more, and a freeze point of−40° C. or less, the composition comprising 90 wt % or more ofisoparaffins.
 2. The composition of claim 1, wherein the compositioncomprises a final boiling point of 300° C. or less.
 3. The compositionof claim 1, wherein the composition comprises 50 wt % or more of C₁₇-C₁₈hydrocarbons.
 4. The composition of claim 1, wherein the compositioncomprises 45 wt % or less of C₁₄-C₁₇ hydrocarbons.
 5. The composition ofclaim 1, wherein the composition comprises 5.0 wt % or less of C₁₉₊hydrocarbons.
 6. The composition of claim 1, wherein the compositioncomprises 1.0 wppm or less of oxygen, or wherein the compositioncomprises 10 wppm or less of sulfur, or a combination thereof.
 7. Thecomposition of claim 1, wherein the composition comprises a renewablejet boiling range composition.
 8. A method for producing a renewable jetboiling range fraction, comprising: contacting a bio-derived feedstockwith a hydrotreatment catalyst under effective hydrotreatment conditionsto produce a deoxygenated effluent comprising a deoxygenated liquidfraction, the bio-derived feedstock comprising 70 wt % or more of C₁₇₊carbon chains; contacting at least a portion of the deoxygenated liquidfraction with a dewaxing catalyst comprising ZSM-48 and Pt, Pd, or acombination thereof under effective dewaxing conditions comprising toproduce an isomerized effluent, the effective dewaxing conditionscomprising a weighted average bed temperature of 300° C. to 350° C., apressure of 1.4 MPa-g to 14 MPa-g, and a LHSV of 1.0 hr⁻¹ to 8.0 hr⁻¹relative to a volume of dewaxing catalyst; and separating the isomerizedeffluent to form a jet boiling range fraction and one or more lowerboiling fractions, the jet boiling range fraction comprising a T90distillation point of 300° C. or less, a freeze point of −40° C. orless, and a flash point of 38° C. or more.
 9. The method of claim 8,wherein a yield of the jet boiling range fraction is 70 wt % or morerelative to a weight of the at least a portion of the deoxygenatedliquid fraction.
 10. The method of claim 8, wherein the jet boilingrange fraction comprises 1.0 wppm or less of oxygen, or wherein the jetboiling range fraction comprises 10 wppm or less of sulfur, or acombination thereof.
 11. The method of claim 8, wherein the jet boilingrange fraction comprises a final boiling point of 300° C. or less. 12.The method of claim 8, wherein the jet boiling range fraction comprises50 wt % or more of C₁₇-C₁₈ hydrocarbons.
 13. The method of claim 8,wherein the bio-derived feedstock comprises 5.0 wt % or less of C₁₉₊carbon chains.
 14. The method of claim 8, wherein the at least a portionof the deoxygenated effluent comprises 80 wt % or more of C₁₇₊n-paraffins.
 15. The method of claim 8, wherein the jet boiling rangefraction comprises less than 45 wt % of C₁₄-C₁₇ hydrocarbons.
 16. Themethod of claim 8, wherein the effective dewaxing conditions comprise aseverity index of 3 to
 9. 17. The method of claim 8, wherein contactingthe bio-derived feedstock with a hydrotreatment catalyst furthercomprises contacting at least a portion of the deoxygenated effluentwith the hydrotreatment catalyst.
 18. The method of claim 8, whereinseparating the isomerized effluent further comprises forming a dieselboiling range fraction, and wherein contacting at least a portion of thedeoxygenated liquid fraction with a dewaxing catalyst comprisescontacting at least a portion of the diesel boiling range fraction withthe catalyst.
 19. The method of claim 8, further comprising separatingthe deoxygenated liquid fraction from the deoxygenated effluent.
 20. Themethod of claim 8, wherein the dewaxing catalyst comprises 0.1 wt % to2.0 wt % of Pt, Pd, or a combination thereof, relative to a weight ofthe dewaxing catalyst.